Needle injection is an invasive method of drug administration, which can cause tissue damage. Also, needle injections may be a source of disease transmission, particularly when needles are reused or misused.
Needle-free injection technologies have gained attention as a means for overcoming the numerous disadvantages of needle injections. Such needle-free injection technologies apply a high pressure to a medicinal fluid to force the fluid out of a small orifice held against a patient's skin. The pressurized medicinal fluid penetrates the skin and enters the tissue under the skin where it is absorbed. Needle-free injection technologies may be used for injecting liquid formulations, as well as drugs and vaccines in a solid particle dosage form. A needle-free injection may prevent skin puncture hazards, bleeding, and bruises. Needle-free injections may ensure a faster drug delivery and better reproducibility and bioavailability in comparison with invasive drug delivery systems.
Some needle-free injection systems use a high-pressure gas such as CO2 for applying the required pressure to the medicinal fluid. Other needle-free injection systems use springs to force the medicinal fluid out of the injection system. These needle-free injection systems apply a fixed amount of force to subcutaneously inject the medicinal fluids to a patient. The amount of force required for a successful subcutaneous injection of the medicine is different for each body type, for example, the amount of force required for an adult is different from that required for a child. As a result, separate needle-free injection systems have been conventionally used for adults and children.
There is, therefore, a need in the art for a needle-free injection system that may be utilized for needle-free injections to different body types. There is further a need in the art for a needle-free injector that allows a user to select the amount of force applied to the medicine based on the patient's body type.